<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
	    <title>我的第二个网页</title>
	    <link rel="stylesheet" href="">
	    <script>
			function displayOrNo(){
				var obj = document.getElementById("blink");
				obj.hidden = !obj.hidden;
				var btn = document.getElementById("control")
				if(obj.hidden){
					btn.innerHTML='显示';
				}else{
					btn.innerHTML='隐藏';
				} 
			} 
		</script>	   
    </head>
	<body>
		<button type="button" id="control" onclick="displayOrNo()">显示
		</button>
		<div id="blink" hidden="hidden">
			Hello,world!
		</div>
	</body>
</html>
